But only if you're used to creating patches. New developers are more likely to know how to create a quick PR than they are to know about creating and submitting patches. I'm not a Python developer either but I know this was one of the considerations after reading the mailing list thread.
It was also addressed in the discussion that developers who prefer to submit patches should still be able to do so, just as they are now. To me, this is the best of both worlds and removes the whole "walled garden" thing.
Github also provides a well documented API and there are multiple services that already plug into it. If they removed that then yes, I would have an issue with the development staying on github. As it stands right now, there's no reason github specific information can't be linked up to external systems, or even integrated with them nicely.
